Field of the Invention
The present invention relates to motor control, and more particularly, to a method, an apparatus and a system for operating a motor based on motor stall detection capable of preventing damage to the motor by controlling an operation of the motor based on motor stall detection.
Discussion of the Related Art
In general, a vehicle includes various motors for convenience of driving, enhancement of fuel efficiency, and passenger convenience. A motor for vehicles restricts limited driving of a driver, and thus requires stall condition control logic, a sensor for the logic, and setting of various limits. In particular, when a position of vehicle equipment such as a seat, an interior side rear view mirror (ISRVM), an exterior side rear view mirror (OSRVM), a rear (RR) curtain, a power window, a wiper motor, etc. needs to be stored or the equipment needs to be driven, there may be difficulty in setting an accurate driving area in each direction and implementing a resolution based on position.
In general, the motor in the vehicle is operated by sensor monitoring and is vulnerable to adjustment of a motor limit value when external noise is applied thereto. In particular, when an initial value of the position of the motor is lost, setting of the driving area may fail. Additionally, overcurrent may occur in the vehicle motor due to a continuous operation and motor stall. When overcurrent continuously occurs, the motor may be damaged. Accordingly, many vehicles include a circuit breaker for blocking supply of power applied to a motor when the motor is overloaded. A device capable of turning power applied to the motor on and off based on whether an abnormal condition, for example, a short circuit condition is detected has been used as the circuit breaker.
Eight schemes described below correspond to representative related art for controlling stall of a motor for vehicles.
In a first scheme, a motor power supply or controller operation stall condition is switched by a disable signal using a limit switch. For example, in a power seat, power applied to a motor may be adjusted by installing an open type limit switch at an end of each rail during a sliding operation, a reclining operation, a tilting operation, etc.
In a second scheme, stall of a motor for vehicles is controlled by setting a stall interval using a voltage resolution based on a sensor input of an alternating current (AC)-direct current (DC) converter (ADC converted) in the motor.
In a third scheme, a motor is stalled under a particular condition by detecting a waveform of a stall current during overrunning of the motor, that is, at the time of reaching a dimensional limit of the motor. For example, the motor may stall when a maximum voltage of a sawtooth wave detected by a stall current sensor exceeds about 60 mV.
In a fourth scheme, driving of a motor is restricted by driving a predetermined timer during continuous operation. For example, when a washer motor is driven, a maximum driving time may be restricted to about 30 seconds in consideration of durability.
In a fifth scheme, a motor is suspended by operating a circuit breaker based on an operating time of the motor. For example, an operating time of a power window motor is calculated, and the motor is suspended by operating a circuit breaker when the calculated operating time is greater than or equal to a predetermined time or longer than a non-operating time.
In a sixth scheme, power supplied to a motor is controlled based on heat generated from the motor. For example, power supplied to a motor is physically blocked using a bimetal when heat is generated by the motor.
In a seventh scheme, driving of a motor is controlled by setting a limit value of a stall current/voltage. For example, when a voltage sensing value of a motor in a direction of a driving shaft is detected to be less than or equal to a predetermined reference value, for example, about 1.5 V during power door cinching, stall is detected and a motor output is blocked.
In an eighth scheme, a driving area of a motor is restricted by setting ranges of a motor driving voltage and a sensor input. For example, a motor driving area may be restricted by setting a voltage sensing value in a direction of a driving shaft of a motor to a range of about 1.5 V to 4.5 V.
Motor detection schemes according to the eight related arts described above have disadvantages in that separate control logic and hardware are required for each device, and a component, which restricts a mechanical driving area of a motor and incurs additional cost, needs to be used. In particular, the bimetal and the limit switch have limitations on cost and setting of physical dimensions, and thus degrees of freedom of component arrangement and wiring are degraded. As a result, there has been a problem of increase in overall volume and weight of the motor. Moreover, the above limited time setting scheme, stall current detection scheme, etc. have a disadvantage in that control accuracy and performance are degraded due to a temperature, a dimensional limit, wear, etc.